Lower bounds for nodal sets of Dirichlet and Neumann eigenfunctions

Let \phi\ be a Dirichlet or Neumann eigenfunction of the Laplace-Beltrami operator on a compact Riemannian manifold with boundary. We prove lower bounds for the size of the nodal set {\phi=0}.Comment: 7 page

EVALUATE E-LEARNING IN IRAQ APPLYING ON AVICENNA CENTER IN ERBIL

The Accelerated growth of information and communication technology and the magnificent evolution in digital technology unlock new Prospects in different dimensions including education one. E-learning is now playing a very important role in learning processes and the major concern in all education institutions and universities. E-Learning approaches are new trends that are based on using computers and information and communication technology as a proxy to deliver and share educational materials which makes education available anytime, and anywhere. Khan suggested eight dimensional e-learning framework which serves as a base to help institutions to plan, design, implement and evaluate their e-learning programs. This paper discusses whether e-learning systems at Avicenna Center in Erbil meet the eight dimensional e-learning frameworks. Also it presents the most critical success steps to develop and evaluate Avicenna center , for the purpose to spread the e-learning in all over Iraq. This research measures the eight dimensional framework and calculates their materiality

EVALUATE E-LEARNING IN IRAQ APPLYING ON AVICENNA CENTER IN ERBIL

The Accelerated growth of information and communication technology and the magnificent evolution in digital technology unlock new Prospects in different dimensions including education one. E-learning is now playing a very important role in learning processes and the major concern in all education institutions and universities. E-Learning approaches are new trends that are based on using computers and information and communication technology as a proxy to deliver and share educational materials which makes education available anytime, and anywhere. Khan suggested eight dimensional e-learning framework which serves as a base to help institutions to plan, design, implement and evaluate their e-learning programs. This paper discusses whether e-learning systems at Avicenna Center in Erbil meet the eight dimensional e-learning frameworks. Also it presents the most critical success steps to develop and evaluate Avicenna center , for the purpose to spread the e-learning in all over Iraq. This research measures the eight dimensional framework and calculates their materiality

A Comprehensive Case Study of Macrosegregation in a Steel Ingot

This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s11663-015-0386-yA case study is presented that examines the macrosegregation and grain structure present in a 12-tonne steel ingot, which was cast for experimental purposes. Details of the casting procedure were well documented and the resulting ingot was characterized using a number of techniques that measured chemical segregation, shrinkage, and porosity. The formation of the porosity and segregation patterns is discussed in reference to the particular grain structure observed in the ingot. It is hoped that this case study can be used as a tool for the validation of future macromodels.This work was undertaken as part of a Project sponsored by Rolls-Royce Power Nuclear plc in collaboration with Sheffield Forgemasters International

Peer influence in network markets: a theoretical and empirical analysis

Network externalities spur the growth of networks and the adoption of network goods in two ways. First, they make it more attractive to join a network the larger its installed base. Second, they create incentives for network members to actively recruit new members. Despite indications that the latter "peer effect" can be more important for network growth than the installed-base effect, it has so far been largely ignored in the literature. We address this gap using game-theoretical models. When all early adopters can band together to exert peer influence-an assumption that fits, e.g., the case of firms supporting a technical standard-we find that the peer effect induces additional growth of the network by a factor. When, in contrast, individuals exert peer influence in small groups of size n, the increase in network size is by an additive constant-which, for small networks, can amount to a large relative increase. The difference between small, local, personal networks and large, global, anonymous networks arises endogenously from our analysis. Fundamentally, the first type of networks is "tie-reinforcing," the other, "tie-creating". We use survey data from users of the Internet services, Skype and eBay, to illustrate the main logic of our theoretical results. As predicted by the model, we find that the peer effect matters strongly for the network of Skype users-which effectively consists of numerous small sub-networks-but not for that of eBay users. Since many network goods give rise to small, local networks

Designing efficient CMUT cells for airborne applications

In this work, we study airborne CMUT cells with vacuum gap where silicon plate is operated both in elastically linear and nonlinear regimes. We report the results of a new mode of operation where the plate center swings the entire gap. The plate is kept in elastically linear region in this mode. Very large pressure levels are obtained at relatively low drive voltage levels. The operation is very efficient but the bandwidth is less than 1%. We considered operating the silicon membrane in elastically nonlinear region for larger bandwidth without sacrificing efficiency. This is achieved by employing the stiffening effect due to the atmospheric pressure. We derived the new model of the CMUT, where the membrane profile deviates from linear profile as a function of the differential static pressure on it. We present the force, the compliance models and the static analysis of stiffened CMUT cells in this work. © 2014 IEEE

MEASUREMENT OF GROUND LEVEL OZONE IN SELECTIVE LOCATIONS IN BAGHDAD CITY

The ground level ozone concentration at different locations in Baghdad city was identified. Five different sites have been chosen to identify the ground level ozone concentration. Al- Dora and Al- Za'afarania were chosen as areas contained point source ( power plant station ) in addition to high traffic load , while Al –Uma park, Aden square and Al-Mawal square were chosen as area contained heavy traffic only (line source). The measurement focuses on spring and fall because these periods display favorable meteorology to ozone formation. During the research period the maximum values (peaks) for ground level ozone concentration were observed at fall: at Al-Za'afarania area 101ppb as an average, at Al-Dora 87 ppb as an average and at line source areas 48 ppb as an average. Among the line sources area Al-Mawal square represent the highest peak value at fall 68 ppb. At spring the peaks of ozone concentration observed to be at the same height, 50 ppb for all sites. The downwind sites from the power plant stations at Al-Dora and Al-Za'afarania areas record higher ozone peaks compared with up wind sites. It can be concluded that the effect of power plant stations in forming ozone is larger than traffic load. The comparison between the ground level ozone concentrations that measured during the research period in spring and fall, and the ambient air quality standards (AAQS) shows that: • No exceeded levels were observed in spring for all sites. • In fall the AAQS for ozone was exceeded in Al-Za'afarania area at 12: PM, 1: PM, 2: PM and 3: PM, and in Al-Dora at 2: PM

EFFECT OF LOW LEVEL LEASER THERAPY ON THE CHRONIC DEFECT OF TIBIAL BONES IN RABBITS

This project was designed to evaluate the effect of low level leaser therapy(LLLT) on the induced chronic defect in the tibial bone of rabbits radiographically ,and physically,eight adults local breed rabbits of both sexes were employed toinduced 2.5 mm in diameter circular defect in the tibial bone surgically under generalanesthesia and highly aseptic technique ,the induced hole was implanted with 2.5 mmstainless steel screw ,that removed from the bone after one and half month postoperation , the experimental animals randomly divided into two equal groups fouranimas of each, the control group was lifted for normal healing process of the bonedefect without any treatment ,while the treatment group was exposed daily with singledosage of continuous diode laser for five minutes of 850 nm and 148.4 j/cm2 at 72hours interval for 14 days post operation (p.o.) ,the radiographic results in thetreatment group showed increase in the bone density around the induced defect withnew bone formation fill the cavity at the end of 2nd week p.o. then increase in thebone density and volume at the end of 4th week p.o. compare with the control groupthat the density and the new bone formation less than treatment group ,the physicalanalysis revealed increase in the bone density and hardiness with significant increasein fractures tolerance in the treatment group compare with the control group .Inconclusion that the LLLT successfully used for repairing the critical ( chronic) defectin tibial bones in rabbits

The Main and Most Important Radiological Role in the Future of the Healthcare Management: A Systematic Theoretical Review

This study aimed at exploring the main and most important Radiological role in the future of the healthcare management through a systematic theoretical review.  As radiology plays the key role of jumping in to investigate dis­ease diagnosing, staging, monitoring and following it over time and offering expertise and consultation on disease states. And highlighting that this discipline is now in a stage of profound metamorphosis through out of building the value of radiology and the radiologist, to empower radiologists to be larger contributors to care teams. The study concluded that the current radiology model, though useful in many respects, needs to adapt to changing economic incentives and in one way or another align itself with those of the clinicians radiologists serve.